1. Field of the Invention
The present invention relates to a refrigerating apparatus used to chill or freeze foods, etc., and more particularly to a refrigerating apparatus for performing hot-water supply simultaneously with cooling.
2. Description of Related Art
As this type of refrigerating apparatus has been broadly used a refrigerating apparatus which includes a compressor, a radiator, a pressure-reducing device and an evaporator and uses a vapor compression type refrigerating cycle using chlorofluorocarbon or the like as refrigerant. According to this refrigerating apparatus, foods, etc. are cooled by utilizing vaporization of refrigerant in the evaporator of the vapor compression type refrigerating cycle, thereby chilling or freezing the foods, etc.
However, with respect to generally broadly used refrigerating apparatuses, cooling waste heat from the refrigerating cycle is discarded from the radiator to atmosphere or the like. In addition, there is such a situation that hot water is supplied and used by using another heat source such as a boiler or the like in facilities where the refrigerating apparatus as described above is installed and used. As described above, the refrigerating apparatuses which have been hitherto broadly used have a problem that the cooling waste heat is not effectively used. Furthermore, the heat radiated from the radiator in the refrigerating apparatus increases the ambient temperature of the refrigerating apparatus, and thus it has been indicated that the refrigerating apparatus is one of factors causing increase of environmental temperature in city areas.
In such a circumstance, it is attempted to perform hot water supply by effectively using cooling waste heat of the refrigerating cycle so that energy saving is implemented (for example, JP-A-2007-303698).
According to a technique disclosed in JP-A-2007-303698, water for hot water supply is heated by a heat pump cycle using atmospheric air as a heat source (first refrigerant flowing in a first refrigerant circuit), and also the water for hot water supply is heated by waste heat from a refrigerating machine for cooling a showcase (second refrigerant flowing in a second refrigerant circuit), whereby the temperature of the water for hot water supply can be increased in short time.
When cooling based on the vapor compression type refrigerating cycle (heat pump cycle) and heating using waste heat caused by the cooling are performed at the same time as described above, the capacity (performance) ratio between cooling and heating is equal to a value which is roughly determined on the refrigeration cycle theory. Therefore, it is necessary to efficiently perform heat-radiating and heat-absorbing to/from the outside of the system in accordance with the actual load of cooling and heating. Particularly, in a system for freezing or chilling foods in a supermarket or the like, the cooling load increases to be larger than the hot water supply load, and thus it is important to provide a efficient heat radiating unit with avoiding complication of the construction of equipment and increase of installation area of equipment and enhance the cooling capacity (power). Furthermore, it is also necessary to enhance the refrigeration cycle efficiency itself and implement further energy saving, and particularly it is required to enhance the cooling efficiency.